package com.cjc.myimageload.lib;

import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.Writer;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import com.cjc.myimageload.R;
import com.cjc.myimageload.tools.Constants;
import com.cjc.myimageload.tools.RequestData;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.widget.ImageView;

public class ImageLoader {
	MemoryCache memoryCache = new MemoryCache();
	FileCache fileCache;
	private Map<ImageView, String> imageViews = Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
	ExecutorService executorService;
	Handler handler = new Handler();// handler to display images in UI thread

	public ImageLoader(Context context) {
		fileCache = new FileCache(context);
		executorService = Executors.newFixedThreadPool(5);
	}

	final int stub_id = R.drawable.iv_error;

	public void displayImage(String url, String time, ImageView imageView) {
		imageViews.put(imageView, url);
		Bitmap bitmap = memoryCache.get(url);
		if (bitmap != null) {
			imageView.setImageBitmap(bitmap);
		} else {
			queuePhoto(url, time, imageView);
			// imageView.setImageResource(stub_id);
		}
	}

	private void queuePhoto(String url, String time, ImageView imageView) {
		PhotoToLoad p = new PhotoToLoad(url, time, imageView);
		executorService.submit(new PhotosLoader(p));
	}

	private Bitmap getBitmap(String url, String time) {
		System.out.println("url:" + url);
		File f = fileCache.getFile(url, time);
		// System.out.println("--------from SD cache------");
		// from SD cache
		Bitmap b = decodeFile(f);
		if (b != null) {
			return b;
		}
		// System.out.println("--------from web------");
		// from web
		try {
			FileOutputStream outStream = null;
			File journalFile = new File(Constants.IMAGEURI, "journal");
			@SuppressWarnings("resource")
			Writer journalWriter = new BufferedWriter(new FileWriter(journalFile, true), (8 * 1024));
			Bitmap bitmap = null;
			// System.out.println("web+url:" + url);
			String filename = String.valueOf(Encrypt.md5(url));
			if (!f.getParentFile().exists()) {
				f.getParentFile().mkdirs();
			}
			if (f.exists()) {
				if (f.length() < 1) {
					f.delete();
				}
			}
			if (!f.exists()) {
				try {
					InputStream inStream = RequestData.getInputStream(url);
					f.createNewFile();
					byte[] data = readInputStream(inStream);
					System.out.println("---length:------" + data.length + "----------");
					outStream = new FileOutputStream(f);
					outStream.write(data);
				} catch (Exception e) {
					// TODO: handle exception
					// System.out.println("**********************" + e);
					File file = new File(Constants.IMAGEURI + filename);
					if (file.exists()) {
						file.delete();
					}
				}
			}
			File file = new File(Constants.IMAGEURI + filename);
			long newLength = file.length();
			// System.out.println("-----newLength----------" + newLength +
			// "----------------");
			journalWriter.write("DIRTY" + ' ' + filename + '\n');
			journalWriter.flush();
			journalWriter.write("CLEAN" + ' ' + filename + ' ' + newLength + '\n');
			journalWriter.flush();
			journalWriter.write("READ" + ' ' + filename + '\n');
			journalWriter.flush();
			bitmap = decodeFile(f);
			if (outStream != null) {
				outStream.close();
			}
			return bitmap;
		} catch (Throwable ex) {
			ex.printStackTrace();
			if (ex instanceof OutOfMemoryError)
				memoryCache.clear();
			return null;
		}

	}

	private static byte[] readInputStream(InputStream inStream) throws Exception {
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] buffer = new byte[1024];
		int len = 0;
		while ((len = inStream.read(buffer)) != -1) {
			outStream.write(buffer, 0, len);
		}
		inStream.close();
		return outStream.toByteArray();
	}

	// decodes image and scales it to reduce memory consumption
	// 解码图像和规模，减少内存消�??
	private Bitmap decodeFile(File f) {
		try {
			// decode image size
			BitmapFactory.Options o = new BitmapFactory.Options();
			o.inJustDecodeBounds = true;
			FileInputStream stream1 = new FileInputStream(f);
			BitmapFactory.decodeStream(stream1, null, o);
			stream1.close();

			// Find the correct scale value. It should be the power of 2.
			// 找到正确的刻度�?��?�它应该�?2的幂�?
			// final int REQUIRED_SIZE = 70;
			// int width_tmp = o.outWidth, height_tmp = o.outHeight;
			int scale = 1;
			// while (true) {
			// if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 <
			// REQUIRED_SIZE)
			// break;
			// width_tmp /= 2;
			// height_tmp /= 2;
			// scale *= 2;
			// }

			// decode with inSampleSize
			BitmapFactory.Options o2 = new BitmapFactory.Options();
			o2.inSampleSize = scale;
			FileInputStream stream2 = new FileInputStream(f);
			Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
			stream2.close();
			return bitmap;
		} catch (FileNotFoundException e) {
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	// Task for the queue
	private class PhotoToLoad {
		public String url;
		public String time;
		public ImageView imageView;

		public PhotoToLoad(String u, String time, ImageView i) {
			this.url = u;
			this.time = time;
			this.imageView = i;
		}
	}

	class PhotosLoader implements Runnable {
		PhotoToLoad photoToLoad;

		PhotosLoader(PhotoToLoad photoToLoad) {
			this.photoToLoad = photoToLoad;
		}

		@Override
		public void run() {
			try {
				if (imageViewReused(photoToLoad))
					return;
				Bitmap bmp = getBitmap(photoToLoad.url, photoToLoad.time);
				memoryCache.put(photoToLoad.url, bmp);
				if (imageViewReused(photoToLoad))
					return;
				BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
				handler.post(bd);
			} catch (Throwable th) {
				th.printStackTrace();
			}
		}
	}

	boolean imageViewReused(PhotoToLoad photoToLoad) {
		String tag = imageViews.get(photoToLoad.imageView);
		if (tag == null || !tag.equals(photoToLoad.url))
			return true;
		return false;
	}

	// Used to display bitmap in the UI thread
	// 用于在UI线程上显示位�?
	class BitmapDisplayer implements Runnable {
		Bitmap bitmap;
		PhotoToLoad photoToLoad;

		public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
			bitmap = b;
			photoToLoad = p;
		}

		public void run() {
			if (imageViewReused(photoToLoad))
				return;
			if (bitmap != null) {
				photoToLoad.imageView.setImageBitmap(bitmap);
			} else {
				photoToLoad.imageView.setImageResource(stub_id);
			}
		}
	}

	public void clearCache() {
		memoryCache.clear();
		// fileCache.clear();
	}
}
